BEIJING, China (CNN) -- Former Chinese Communist Party chief Zhao Ziyang, who was ousted amid the upheaval surrounding the 1989 Tiananmen Square crackdown on pro-democracy protesters, has died at the age of 85, the state news agency Xinhua has announced.

Zhao had suffered from respiratory and cardiovascular problems and died early Monday in a Beijing hospital, Xinhua said.

Zhao was considered one of the standard-bearers of political and economic reform in China.

He opposed the use of force against the Tiananmen Square demonstrators and was removed from his post during the clampdown.

The former leader had been kept under house arrest until his death.

CNN's Beijing Bureau Chief Jaime Florcruz reported that there was no indication Zhao's death had triggered any public show of sympathy on the streets of the capital shortly after his death was announced on Monday.

Most Chinese will remember Zhao as a well-meaning, honest official, Florcruz said, but as someone who was not good at political maneuvering.

"He was a very pragmatic leader, and he was very successful in provincial level market reforms in the early years," said Tang Wenfang, a professor of political science at the University of Pittsburgh.

In the late 1980s, when Zhao rose to become China's premier and later party chief, he stood out by pushing political reforms, but he clashed with conservative leaders as students gathered to agitate for freedom and democracy.

He was last seen in public in May 1989, when he visited hunger strikers at the Square.

"We have come too late," he tearfully told the students.

But Zhao may have been too early for his time, political analysts say.

"Hard-line conservative leaders were not ready for market reform, and so there was a lot of ideological resistance to his initiatives, policy initiatives," Tang said.

"On the other hand the ordinary people were not ready to absorb the cost of market reform, such as inflation, unemployment, corruption, all those negative, unintended consequences of market reform.

"He was purged, accused of sympathizing with the protesters and splitting the Communist Party," Tang said.

Zhai Weimin, one of the leaders of the Tiananmen Square protests, said Zhao was "a daring and resolute reformer ... but he was not as good at political maneuvering as the other leaders were."

For years following his ouster, Zhao remained under house arrest inside his closely guarded Beijing courtyard.

Zhao was rarely allowed to step out, except to play occasional rounds of golf. Even out of power in his twilight years, he remained a threat to the leaders who followed him.